Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds

Moyer, M.W.

Oak Ridge National Laboratory

关键词: 30 Direct Energy Conversion;    Wave Forms;    Lanl;    Y-12 Plant Nesdps Office Of Nuclear Energy Space And Defense Power Systems;    Fuel Pellets;   

DOI  :  10.2172/777634
RP-ID  :  ORNL/TM-2001/9
RP-ID  :  AC05-96OR22464
RP-ID  :  777634

美国|英语

来源: UNT Digital Library

【 摘 要 】

A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.